GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 1997 🢒 Yukon - 4WD 🢒 Engine 🢒 Engine Controls - 6.5L 🢒 DTC P0237 Turbocharger Boost Sensor Circuit Low Voltage

Refer to

DIESEL PCM, EGR, SENSORS


Object Number: 52761 Size: FS
Engine Controls Components
DIESEL PCM, MAF, EGR, APP, WASTEGATE
DIESEL PCM, CKP, FUEL TEMP, ITS
OBD II Symbol Description Notice
DIESEL PCM, CKP, FUEL TEMP, ITS
DIESEL 4L80E PCM, TRANSMISSION, SOLENOIDS
Handling Electrostatic Discharge Sensitive Parts Notice
Handling Electrostatic Discharge Sensitive Parts Notice

Circuit Description

The powertrain control module (PCM) controls boost using the turbocharger wastegate solenoid. The solenoid is pulse width modulated (PWM). When the wastegate solenoid is not energized, the vacuum to the turbocharger wastegate solenoid is vented to atmosphere through the solenoid. As the pulse width is increased by the PCM, more vacuum is applied through the solenoid to the wastegate actuator. At idle a higher vacuum to the wastegate actuator helps keep the wastegate closed. At higher engine speeds the vacuum supplied by the solenoid is less, allowing the turbocharger boost pressure to overcome the wastegate actuator.

Conditions for Setting the DTC
    • Boost Pressure less than 40 kPa.
    • Condition met for 2 seconds.

Action Taken When the DTC Sets

The MIL will be illuminated after 2 test failures.

Conditions for Clearing the MIL/DTC
    • The PCM will turn the MIL off after three consecutive trips without a fault condition.
    • A History DTC will clear when forty consecutive warm-up cycles that the diagnostic does not fail (coolant temperature has risen 5°C (40°F) from start up coolant temperature and engine coolant temperature exceeds 71°C (160°F) that same ignition cycle.
    • Use of a Scan Tool

Diagnostic Aids

Very little boost can be attained by revving the engine in neutral. If the Boost sensor signal circuit is open or shorted to ground, Boost solenoid will show a zero duty cycle. A

An intermittent may be caused by the following:

    • Poor connections.
    • Rubbed through wire insulation.
    • Broken wire inside the insulation.

Test Description

Number(s) below refer to the step number(s) on the Diagnostic Table.

  1. This step will determine if DTC P0237 is the result of a hard failure or an intermittent condition.

    2.

  2. This step simulates conditions for a DTC P0237. If the PCM recognizes the change, the PCM and signal circuit are OK.

    3.

  3. In this step, components that share the 5 volt reference can cause the reference voltage to be shorted to ground. This can be checked by disconnecting each component that shares the 5 volt reference one at a time, including the PCM while checking for continuity on that circuit to chassis ground.

Step

Action

Value(s)

Yes

No

1

Important: Before clearing DTCs use the scan tool Capture Info to record freeze frame and failure records for reference, as data will be lost when Clear Info function is used.

Was the Powertrain On-Board Diagnostic (OBD) system check performed?

--

Go to Step 2

Go to Powertrain On Board Diagnostic (OBD) System Check

2
  1. Scan tool connected.
  2. Engine idling.
  3. Observe Boost pressure display on scan tool

Does the scan tool display a Boost Pressure less than or equal to the specified value?

40 kPa

Go to Step 3

Go to Step 5

3
  1. Turn the ignition OFF.
  2. Disconnect the Boost sensor electrical connector.
  3. Jumper the Boost sensor 5 volt reference to the Boost sensor signal circuit at the harness.
  4. Turn the ignition ON.

Does the scan tool display a Boost Pressure greater than or equal to the specified value?

202 kPa

Go to Step 6

Go to Step 4

4
  1. Turn the ignition OFF.
  2. The Boost sensor still disconnected.
  3. Remove the jumper wire.
  4. Probe the Boost sensor signal circuit at the harness with a test light connected to B+.
  5. Turn the ignition ON.

Does the scan tool display a Boost Pressure greater than or equal to the specified value?

202 kPa

Go to Step 8

Go to Step 7

5

The DTC is intermittent. If no additional DTCs are stored, refer to Diagnostic Aids. If additional DTCs are stored, refer to those table(s) first.

Are any additional DTCs stored?

--

Go to the Applicable DTC Table

Go to Diagnostic Aids

6
  1. Check for a poor connection at the Boost sensor.
  2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 13

Go to Step 10

7
  1. Check for the following in Boost sensor signal circuit.
    2. • For an open.
    • For a short to ground.
  2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 13

Go to Step 11

8
  1. Check for an open in the Boost sensor 5 volt reference circuit.
  2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 13

Go to Step 9

9
  1. Check for a short to ground in the Boost sensor 5 volt reference circuit.
  2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 13

Go to Step 12

10

Replace the Boost sensor. Refer to Boost Sensor (Diesel) .

Is the action complete?

--

Go to Step 13

--

11
  1. Check the terminal connectors at the PCM for a poor connections.
  2. If a problem is found, repair as necessary.

Was a problem found?

--

Go to Step 13

Go to Step 12

12

Replace the PCM.

Important: The new PCM must be programmed. Refer to Powertrain Control Module Replacement/Programming .

Is the action complete?

--

Go to Step 13

--

13
  1. Using the Scan Tool, select DTC, Clear Info.
  2. Start engine and idle at normal operating temperature.
  3. Select DTC, Specific, then enter the DTC number which was set.
  4. Operate the vehicle until the Scan Tool indicates that the diagnostic Ran.

Does the Scan Tool indicate that this diagnostic Passed?

--

Go to Step 14

Go to Step 2

14

Using the Scan Tool, select Capture Info, Review Info.

Are any DTCs displayed that have not been diagnosed?

--

Go to the Applicable DTC Table

System OK